Will apple remove engraving from ipad which is returned?

Remember, you are not asking Apple here but other end users. If you want an official answer, you need to contact Apple.

However, I believe this description of the iPad refurb process confirms all unit turned into refurbs get a new case:

from Learn more about each refurbished iPad.

According to Apple's page, it can be returned, but only directly to Apple.

Returns & Refunds - Shopping Help - Apple

Main point from the link above:

Exchange an item

If you purchased your item from Apple in the U.S., you can take it to any U.S. Apple Store for an exchange. Item exchanges are, of course, subject to in-store product availability. It's a good idea to check if a product is in stock by visiting apple.com and then seeing if it's available for pickup at a store nearby. The only exchange exceptions are personalized items (such as engraved iPad or AirPods) and Macs that have been custom-configured. These items cannot be exchanged in store; they can only be returned and your refund will be issued to the payment method you used on your order (per the guidelines in our Standard Return Policy).